2017-11-13 22:40 GMT+08:00 Paolo Bonzini <pbonzini@redhat.com>:> UMIP can be emulated almost perfectly on Intel processor by enabling> descriptor-table exits. SMSW does not cause a vmexit and hence it> cannot be changed into a #GP fault, but all in all it's the most> "innocuous" of the unprivileged instructions that UMIP blocks.>> In fact, Linux is _also_ emulating SMSW instructions on behalf of the> program that executes them, because some 16-bit programs expect to use> SMSW to detect vm86 mode, so this is an even smaller issue.>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>